fix #784, check storage permission before trying to import settings

app/src/main/kotlin/com/simplemobiletools/calendar/pro/activities/SettingsActivity.kt

@@ -692,14 +692,18 @@ class SettingsActivity : SimpleActivity() {
 
     private fun setupImportSettings() {
         settings_import_holder.setOnClickListener {
-            FilePickerDialog(this) {
-                Thread {
-                    try {
-                        parseFile(it)
-                    } catch (e: Exception) {
-                        showErrorToast(e)
+            handlePermission(PERMISSION_READ_STORAGE) {
+                if (it) {
+                    FilePickerDialog(this) {
+                        Thread {
+                            try {
+                                parseFile(it)
+                            } catch (e: Exception) {
+                                showErrorToast(e)
+                            }
+                        }.start()
                     }
-                }.start()
+                }
             }
         }
     }